Each day thousands of Americans are victims of cardiac emergencies. Cardiac emergencies typically strike without warning, oftentimes striking people with no history of heart disease. The most common cardiac emergency is sudden cardiac arrest (“SCA”). It is estimated more than 1000 people per day are victims of SCA in the United States alone.
SCA occurs when the heart stops pumping blood. Usually SCA is due to abnormal electrical activity in the heart, resulting in an abnormal rhythm (arrhythmia). One such abnormal rhythm, ventricular fibrillation (VF), is caused by abnormal and very fast electrical activity in the heart. During VF the heart cannot pump blood effectively. Because blood may no longer be pumping effectively during VF, the chances of surviving decreases with time after the onset of the emergency. Brain damage can occur after the brain is deprived of oxygen for four to six minutes.
Applying an electric shock to the patient's heart through the use of a defibrillator treats VF. The shock clears the heart of the abnormal electrical activity (in a process called “defibrillation”) by depolarizing a critical mass of myocardial cells to allow spontaneous organized myocardial depolarization to resume.
Cardiac arrest is a life-threatening medical condition that may be treated with external defibrillation. External defibrillation includes applying electrodes to the patient's chest and delivering an electric shock to the patient to depolarize the patient's heart and restore normal sinus rhythm. The chance a patient's heart can be successfully defibrillated increases significantly if a defibrillation pulse is applied quickly.
In a scenario where a paramedic is responding to an emergency call with a non-specific patient condition, for example, there has been a car accident. The paramedic will typically carry his or her own defibrillator/monitor, a gurney, and drug box, and other supplies considered essential. If, perhaps, the car has driven off an embankment, the paramedic will have a long distance to run with all this equipment. This slows the response time to a call where someone may be bleeding to death. Smaller lighter equipment is always demanded by paramedics to save them time and effort, and allow them to get to the scene earlier. For just this reason, some paramedics will opt to carry only an AED (Automatic External Defibrillator) to the scene, and move the patient into the ambulance as quickly as possible, where other, more advanced monitoring equipment is available. In some countries, this approach has been incorporated into standard operating protocols, where the ambulance carries both ALS (advanced life support) equipment (which typically would include a multi-parameter monitor and defibrillator) and an AED. This approach, while effectively giving the user the choice of equipment to carry, forces the paramedic to learn two different defibrillators. The approach also forces the paramedics to possibly transfer the patient from one machine to the other once in the ambulance. It also adds costs to the ambulance service and potentially causes lost data between the two defibrillators for critical minutes, which may negatively impact the ability of EP Lab (Electro-Physiology Lab) doctors to determine the original cardiac condition.
Previous attempts to address the issue of product weight have done so by creating a manual defibrillator that separates from a patient monitor, or an AED, which separates from a single-channel patient monitor, or a manual defibrillator/pacemaker that separates from a 12-lead ECG monitor. These products suffer from limitations by the present standards, such as: limited capture of patient data, limited ability to monitor all necessary patient vital signs, and possible unreliability due to the nature of the electrical contacts between the two devices (e.g., dirt, mud, and damage to the case which could affect alignment of electrical contacts, thus preventing full functionality of the devices when mated).
In a scenario where a patient on a gurney is being transported through narrow doorways and down stairwells to an ambulance, or the situation where a patient is in an ambulance moving on a road at high speed with patient cables and IV (intravenous) lines running between the patient and other equipment within the ambulance. If the monitoring/therapeutic device is large or the route to the ambulance is particularly difficult, the paramedic might elect to carry the device separately from the gurney to prevent the device falling off the gurney or onto the patient. However, the paramedic is now restricted in his or her ability to detach the device from the gurney due to the number and length of patient cables between the device and the patient. Similar restrictions occur once the patient is loaded into a patient transport vehicle or when the patient is transferred from the ambulance to the emergency department. The number of cables and their similarity in color or dissimilarity in length can all contribute to delays in treating or transferring the patient and can restrict the paramedics mobility when treating the patient in a confined space. Additionally, delays may be created with cables having become tangled, or even cut, from their previous uses.
The prior art has tried to solve this problem by providing a wireless module that transmits data to a patient monitor, such as the MobiMed offered for Sale by Ortivus. However, this device does not include a defibrillator and does not have the capability to provide any therapeutic functions such as pacing, defibrillation or synchronous cardioversion without attaching another monitor/defibrillator to the patient, which further increases the complexity and ambulance provider cost. Additionally, the Ortivus patient module does not offer replaceable batteries so functionality is severely limited if a reliable source of battery charging is not available, or if the transport time is excessively long. Additionally, the Ortivus device does not offer a display to allow visual monitoring of the waveforms or vital signs if the other module is out of range or obscured.